tailwindlabs · RobinMalfait · Feb 17, 2026 · Feb 15, 2026 · Feb 17, 2026 · Feb 17, 2026
@@ -29,6 +29,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Allow multiples of `.25` in `aspect-*` fractions ([#19688](https://github.com/tailwindlabs/tailwindcss/pull/19688))
 - Ensure changes to external files listed via `@source` trigger a full page reload when using `@tailwindcss/vite` ([#19670](https://github.com/tailwindlabs/tailwindcss/pull/19670))
 - Improve performance Oxide scanner in bigger projects ([#19632](https://github.com/tailwindlabs/tailwindcss/pull/19632))
+- Ensure import aliases in Astro v5 work without crashing ([#19677](https://github.com/tailwindlabs/tailwindcss/issues/19677))
 
 ### Deprecated
 

@@ -1,4 +1,4 @@
-import { candidate, fetchStyles, html, js, json, retryAssertion, test, ts } from '../utils'
+import { candidate, css, fetchStyles, html, js, json, retryAssertion, test, ts } from '../utils'
 
 test(
   'dev mode',
@@ -129,3 +129,73 @@ test(
     await fs.expectFileToContain(files[0][0], [candidate`underline`, candidate`overline`])
   },
 )
+
+// https://github.com/tailwindlabs/tailwindcss/issues/19677
+test(
+  'import aliases should work in <style> blocks',
+  {
+    fs: {
+      'package.json': json`
+        {
+          "type": "module",
+          "dependencies": {
+            "astro": "^5",
+            "@tailwindcss/vite": "workspace:^",
+            "tailwindcss": "workspace:^"
+          }
+        }
+      `,
+      'astro.config.mjs': ts`
+        import tailwindcss from '@tailwindcss/vite'
+        import { defineConfig } from 'astro/config'
+
+        // https://astro.build/config
+        export default defineConfig({
+          vite: { plugins: [tailwindcss()] },
+        })
+      `,
+      'tsconfig.json': json`
+        {
+          "extends": "astro/tsconfigs/strict",
+          "include": [".astro/types.d.ts", "**/*"],
+          "exclude": ["dist"],
+          "compilerOptions": {
+            "paths": {
+              "@styles/*": ["./src/styles/*"]
+            }
+          }
+        }
+      `,
+      // prettier-ignore
+      'src/pages/index.astro': html`
+        ---
+        import '@styles/global.css'
+        ---
+
+        <html lang="en">
+          <head>
+            <meta charset="utf-8" />
+            <meta name="viewport" content="width=device-width" />
+            <meta name="generator" content={Astro.generator} />
+            <title>Astro</title>
+            <style>
+              @reference "@styles/global.css";
+            </style>
+          </head>
+          <body>
+            <h1 class="underline">Astro</h1>
+          </body>
+        </html>
+      `,
+      'src/styles/global.css': css`@import 'tailwindcss';`,
+    },
+  },
+  async ({ fs, exec, expect }) => {
+    await exec('pnpm astro build')
+
+    let files = await fs.glob('dist/**/*.css')
+    expect(files).toHaveLength(1)
+
+    await fs.expectFileToContain(files[0][0], [candidate`underline`])
+  },
+)
@@ -12,7 +12,13 @@ import { Scanner } from '@tailwindcss/oxide'
 import { realpathSync } from 'node:fs'
 import fs from 'node:fs/promises'
 import path from 'node:path'
-import type { Environment, Plugin, ResolvedConfig, ViteDevServer } from 'vite'
+import type {
+  Environment,
+  InternalResolveOptions,
+  Plugin,
+  ResolvedConfig,
+  ViteDevServer,
+} from 'vite'
 import * as vite from 'vite'
 
 const DEBUG = env.DEBUG
@@ -59,8 +65,36 @@ export default function tailwindcss(opts: PluginOptions = {}): Plugin[] {
       customCssResolver = (id: string, base: string) => cssResolver(id, base, true, isSSR)
       customJsResolver = (id: string, base: string) => jsResolver(id, base, true, isSSR)
     } else {
+      type ResolveIdFn = (
+        environment: Environment,
+        id: string,
+        importer?: string,
+        aliasOnly?: boolean,
+      ) => Promise<string | undefined>
+
+      // There are cases where Environment API is available,
+      // but `createResolver` is still overriden (for example astro v5)
+      //
+      // Copied as-is from vite, because this function is not a part of public API
+      //
+      // TODO: Remove this function and pre-environment code when Vite < 7 is no longer supported
+      function createBackCompatIdResolver(
+        config: ResolvedConfig,
+        options?: Partial<InternalResolveOptions>,
+      ): ResolveIdFn {
+        const compatResolve = config.createResolver(options)
+        let resolve: ResolveIdFn
+        return async (environment, id, importer, aliasOnly) => {
+          if (environment.name === 'client' || environment.name === 'ssr') {
+            return compatResolve(id, importer, aliasOnly, environment.name === 'ssr')
+          }
+          resolve ??= vite.createIdResolver(config, options)
+          return resolve(environment, id, importer, aliasOnly)
+        }
+      }
+
       // Newer Vite versions
-      let cssResolver = vite.createIdResolver(env.config, {
+      let cssResolver = createBackCompatIdResolver(env.config, {
         ...env.config.resolve,
         extensions: ['.css'],
         mainFields: ['style'],
@@ -69,7 +103,7 @@ export default function tailwindcss(opts: PluginOptions = {}): Plugin[] {
         preferRelative: true,
       })
 
-      let jsResolver = vite.createIdResolver(env.config, env.config.resolve)
+      let jsResolver = createBackCompatIdResolver(env.config, env.config.resolve)
 
       customCssResolver = (id: string, base: string) => cssResolver(env, id, base, true)
       customJsResolver = (id: string, base: string) => jsResolver(env, id, base, true)